1. Field of the Invention
This disclosure is generally related to power conversion, and particularly to bi-directional power conversion via a DC/DC switch mode power converter.
2. Description of the Related Art
A variety of applications employ DC/DC power conversion to, for example, step-up and/or step-down voltage. For example, electric drive or hybrid automotive applications may at times provide power from a high voltage DC source, such as one or more fuel cells, to supply low voltage DC loads and/or to recharge one or more batteries and/or ultracapacitors. During other times, a low voltage power source, such as one or more of the batteries and/or ultracapacitors, may provide power to a high voltage DC load, such as an electric traction motor coupled to drive one or more wheels via a drivetrain.
Switch mode converters typically offer higher efficiency than linear regulators, and can step-up or step-down the input voltage. In some embodiments, switch mode converters can even invert the input voltage. A variety of switch mode DC/DC converter topologies and operation of the same are known to those of skill in the art. For example, buck converters for stepping down the input voltage, boost converters for stepping up the input voltage, as well as buck-boost converters and flyback converters for alternatively stepping down and stepping up the input voltage.
DC/DC switch mode converter operation is typically limited by thermal constraints, such as the ability to dissipate heat generated by the conversion process. This may be disadvantageous, particularly where some flexibility is desired in the load pattern during boost mode operation of the DC/DC converter. It would thus be desirable to increase the flexibility of operation of the DC/DC converter, while avoiding thermal damage to the DC/DC converter from excessive accumulation of heat.